The city of Smolyan is located in the central part of the Rhodope Mountains in southern Bulgaria. It is 87 km west of Kardzhali, 245 km from the capital Sofia, 96 km south of Plovdiv, 436 km from Varna, and 319 km from Burgas. It occupies a large part of the Cherna River valley, straddling both banks of the river from west to east. Summers are cool and humid, winters are mild, springs are cool, and autumns are sunny and warm. Smolyan is dominated by easterly winds.

Smolyan is the seat of the episcopal vicariate of the Plovdiv Diocese of the Bulgarian Orthodox Church. Since 19 April 2008, after decades of devolution, Smolyan has been elevated to a diocese, headed by Bishop Anthony of Constantinople. At the same time, the new bishop remains under the auspices of the Plovdiv Diocese of the Bulgarian Orthodox Church.

The city of Smolyan also hosts the headquarters of the regional mufti's office, the permanent regional executive body of the Grand Mufti's Office of Sofia, which represents the Muslim community in Bulgaria. There are two active mosques in Smolyan, one in the Gorno Vlahovo and the other in the Kaptazha districts.

After 1991, Protestants (Adventists and Evangelicals) also began living in Smolyan.